O objetivo deste trabalho foi avaliar a taxa de sucesso, a quantidade de perda óssea em altura e a interação osso/implante para três diferentes protocolos: 1) implantes osseointegráveis mantidos sem carga durante período de reparo de 120 dias; 2) implantes submetidos a interferências oclusais; e 3) implantes que receberam carga imediata para ancoragem ortodôntica. Foram utilizados doze minipigs BR-1, nos quais foram instalados 70 implantes osseointegráveis de titânio (3,75mm diâmetro x 8,50mm comprimento), divididos em 5 grupos: Grupo 1 (n=12), implantes sem carga sepultados na mesial de caninos; Grupo 2 (n=6), implantes sem carga em áreas de extração; Grupo 3 (n=12), implantes expostos a interferências oclusais; Grupo 4 (n=20), implantes submetidos à carga ortodôntica imediata; Grupo 5 (n=20), implantes instalados em áreas de extração e submetidos à carga ortodôntica imediata. Ao término do período experimental, os animais foram eutanasiados e biópsias da região de interesse coletadas. Realizou-se avaliação clínica para estabelecer a porcentagem de sucesso (Teste Exato de Fisher), análise radiográfica para quantificar a perda óssea em altura (programa de análise de imagens KS300-Zeiss®, ANOVA) e análise histológica para descrever as características da interface osso/implante. A análise dos dados demonstrou: 1) Grupos 1, 2, 4 e 5 - taxa de sucesso, quantidade de perda óssea em altura e interação osso/implante semelhantes; 2) Grupo 3 - taxa de insucesso e quantidade de perda óssea significantemente maiores que os demais grupos, além de apresentar ausência de interação osso/implante. Os resultados clínicos, radiográficos e histológicos revelados nos grupos submetidos à carga ortodôntica imediata em relação aos grupos sem carga demonstraram que a perda óssea na região da crista óssea periimplantar é aceitável e não compromete a estabilidade clínica dos implantes. Desta forma, a utilização de carga imediata para ancoragem em Ortodontia não prejudica a posterior utilização desses implantes para a reabilitação protética, objetivo primário da indicação deste protocolo. Estudos clínicos prospectivos são necessários para comprovar estes dados. / This research aimed at evaluating the success rate, the bone height loss, and the bone/implant interface in three different protocols: 1) osseointegrated implants maintained without load during a repair period of 120 days; 2) osseointegrated implants submitted to occlusal interferences; and 3) immediately loaded osseointegrated implants for orthodontic anchorage. Twelve BR-1 minipigs were used, in which 70 osseointegrated titanium implants were inserted (3.75mm diameter x 8.50mm length), divided into 5 groups: Group 1 (n=12), submerged implants without load; Group 2 (n=6), implants without load in extraction sites; Group 3 (n=12), implants exposed to occlusal interferences; Group 4 (n=20), exposed implants submitted to immediate orthodontic load; Group 5 (n=20), exposed implants inserted in extraction sites and submitted to immediate orthodontic load. At the end of the experimental period, the animals were euthanized and biopsies of the areas of interest were harvested. The clinical analysis (Exact Fisher Test) revealed the success rate of the inserted implants, the radiographic analysis quantified the bone height loss (image analysis program KS300-Zeiss®, ANOVA), and the histological analysis showed the bone/implant interface characteristics. The data analysis revealed: 1) Groups 1, 2, 4 and 5 - similar success rate, bone height loss and bone/implant interface characteristics; 2) Group 3 - statistically greater fail rate and bone height loss, and absence of bone/implant interaction characteristics. Clinical, radiographic and histological results presented in the groups submitted to immediate orthodontic load compared with the other without load demonstrated that the bone loss in the bone crest area is acceptable, and does not compromise the clinical stability of the implants. Therefore, the use of immediate load for orthodontic anchorage did not jeopardize the subsequent use of the implants for oral prosthetic rehabilitation, the main objective of this protocol. Further clinical studies are necessary to confirm these data.

O objetivo deste trabalho foi avaliar a taxa de sucesso, a quantidade de perda óssea em altura e a interação osso/implante para três diferentes protocolos: 1) implantes osseointegráveis mantidos sem carga durante período de reparo de 120 dias; 2) implantes submetidos a interferências oclusais; e 3) implantes que receberam carga imediata para ancoragem ortodôntica. Foram utilizados doze minipigs BR-1, nos quais foram instalados 70 implantes osseointegráveis de titânio (3,75mm diâmetro x 8,50mm comprimento), divididos em 5 grupos: Grupo 1 (n=12), implantes sem carga sepultados na mesial de caninos; Grupo 2 (n=6), implantes sem carga em áreas de extração; Grupo 3 (n=12), implantes expostos a interferências oclusais; Grupo 4 (n=20), implantes submetidos à carga ortodôntica imediata; Grupo 5 (n=20), implantes instalados em áreas de extração e submetidos à carga ortodôntica imediata. Ao término do período experimental, os animais foram eutanasiados e biópsias da região de interesse coletadas. Realizou-se avaliação clínica para estabelecer a porcentagem de sucesso (Teste Exato de Fisher), análise radiográfica para quantificar a perda óssea em altura (programa de análise de imagens KS300-Zeiss®, ANOVA) e análise histológica para descrever as características da interface osso/implante. A análise dos dados demonstrou: 1) Grupos 1, 2, 4 e 5 - taxa de sucesso, quantidade de perda óssea em altura e interação osso/implante semelhantes; 2) Grupo 3 - taxa de insucesso e quantidade de perda óssea significantemente maiores que os demais grupos, além de apresentar ausência de interação osso/implante. Os resultados clínicos, radiográficos e histológicos revelados nos grupos submetidos à carga ortodôntica imediata em relação aos grupos sem carga demonstraram que a perda óssea na região da crista óssea periimplantar é aceitável e não compromete a estabilidade clínica dos implantes. Desta forma, a utilização de carga imediata para ancoragem em Ortodontia não prejudica a posterior utilização desses implantes para a reabilitação protética, objetivo primário da indicação deste protocolo. Estudos clínicos prospectivos são necessários para comprovar estes dados. / This research aimed at evaluating the success rate, the bone height loss, and the bone/implant interface in three different protocols: 1) osseointegrated implants maintained without load during a repair period of 120 days; 2) osseointegrated implants submitted to occlusal interferences; and 3) immediately loaded osseointegrated implants for orthodontic anchorage. Twelve BR-1 minipigs were used, in which 70 osseointegrated titanium implants were inserted (3.75mm diameter x 8.50mm length), divided into 5 groups: Group 1 (n=12), submerged implants without load; Group 2 (n=6), implants without load in extraction sites; Group 3 (n=12), implants exposed to occlusal interferences; Group 4 (n=20), exposed implants submitted to immediate orthodontic load; Group 5 (n=20), exposed implants inserted in extraction sites and submitted to immediate orthodontic load. At the end of the experimental period, the animals were euthanized and biopsies of the areas of interest were harvested. The clinical analysis (Exact Fisher Test) revealed the success rate of the inserted implants, the radiographic analysis quantified the bone height loss (image analysis program KS300-Zeiss®, ANOVA), and the histological analysis showed the bone/implant interface characteristics. The data analysis revealed: 1) Groups 1, 2, 4 and 5 - similar success rate, bone height loss and bone/implant interface characteristics; 2) Group 3 - statistically greater fail rate and bone height loss, and absence of bone/implant interaction characteristics. Clinical, radiographic and histological results presented in the groups submitted to immediate orthodontic load compared with the other without load demonstrated that the bone loss in the bone crest area is acceptable, and does not compromise the clinical stability of the implants. Therefore, the use of immediate load for orthodontic anchorage did not jeopardize the subsequent use of the implants for oral prosthetic rehabilitation, the main objective of this protocol. Further clinical studies are necessary to confirm these data.

Orientador: Altair Antoninha Del Bel Cury / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-22T21:13:35Z (GMT). No. of bitstreams: 1 Cavalcanti_IndiraMoraesGomes_M.pdf: 1420347 bytes, checksum: 8abf0fb5ddb8408095a6916cf3badd0a (MD5) Previous issue date: 2013 / Resumo: Tratamentos que alteram propriedades de superfície de titânio são realizados em implantes odontológicos visando uma melhor sinalização celular e a neoformação óssea. Porém, em determinadas situações clínicas, as superfícies de titânio expostas ao meio oral recobertas por película adquirida (PA) podem se tornar substratos para o desenvolvimento de biofilmes associados às doenças inflamatórias, como a peri-implantite. Diante desta observação, os objetivos deste estudo foram (i) caracterizar a superfície de titânio nitretada por plasma a frio quanto às propriedades de rugosidade, topografia, composição química e energia livre de superfície (ELS); (ii) determinar o perfil protéico da PA adsorvida às superfícies (iii) avaliar a influência do tratamento de superfície na formação e desenvolvimento de biofilmes multiespécies. Para o estudo, discos de titânio grau IV receberam polimento e acabamento e foram divididos aleatoriamente no grupo controle (Ti) e experimental TiN (nitretado por plasma a frio). As superfícies foram caracterizadas através da microscopia eletrônica de varredura (MEV) e a rugosidade e topografia determinadas pela Microscopia de Força Atômica (n = 4). A ELS foi avaliada pela técnica ácido-base e leitura em goniômetro (n = 9) e a composição química da superfície foi determinada por Espectroscopia Fotoeletrônica de Raios-X (XPS) (n = 4). Em seguida, os discos foram imersos em saliva para formação de PA por 2 horas e novamente a ELS foi determinada (n = 6). O perfil protéico da PA foi determinado por espectrometria de massas LC-MS/MS (n = 18). Um biofilme composto por um fungo e seis bactérias (Candida albicans, Veillonella dispar, Streptococcus mutans, Streptococcus oralis, Fusubacterium nucleatum e Actinomyces naeslundii), foi desenvolvido durante 64,5 horas sobre os discos com película. Após este período, os micro-organismos e o biofilme total foram quantificados em células viáveis (n = 12). A topografia e a organização dos biofilmes foram analisadas por MEV e pela microscopia confocal a laser. Os dados de células viáveis e perfil protéico foram avaliados estatisticamente pelo Teste t de Student e os dados de ELS pela análise de variância (ANOVA) de dois fatores seguida pelo teste de Tukey com nível de significância de 5 %. Os resultados demonstraram não haver diferença entre as propriedades de rugosidade e topografia entre os grupos e um maior pico de nitrogênio foi detectado na composição química da superfície nitretada. O tratamento não alterou a ELS, que aumentou apenas na presença de PA (p < 0.001). Diferentes proteínas se adsorveram a superfície nitretada. A quantidade de células viáveis do biofilme formado nas duas superfícies foi semelhante (p = 0.416), confirmado pelas microscopias, porém Fusobacterium nucleatum e Streptococcus oralis foram quantificados em maior número nos biofilmes do grupo TiN. Conclui-se que a nitretação por plasma a frio não alterou as propriedades de superfície de titânio e não influenciou a quantidade de biofilme formado. Porém, a superfície nitretada aumentou as contagens de Fusobacterium nucleatum e Streptococcus oralis e selecionou diferentes proteínas na PA / Abstract: Surface treatments that alter titanium properties titanium are performed on dental implants in order to improve the cell signalization and bone formation. Although, in certain clinical situations, the surfaces exposed to oral cavity covered by acquired-pellicle (AP) may become substrates for development of biofilms associated with inflammatory diseases as periimplantitis. Given this observation, the aims of this study were (i) to characterize the surface properties of titanium nitride by cold plasma as roughness, topography, chemical composition and surface free energy (SFE), (ii) determine the protein profile of AP adsorbed to the surfaces (iii) evaluate the influence of surface treatment on formation and development of multispecies biofilms. For the study, titanium discs grade IV received polish and finish and were randomly allocated to control (Ti) and experimental TiN (nitride by cold-plasma) groups. The surfaces were characterized by scanning electron microscopy (SEM) and roughness and topography determined by Atomic Force Microscopy (n = 4). The SFE was evaluated using the acid-base technique and read in goniometer (n = 9). The surface chemical composition was determined by x-ray photo-electron spectroscopy (XPS) (n = 4). Then, the discs were immersed in saliva for AP formation per 2 hours and again the SFE was determined (n = 6). The AP protein profile was determined by mass spectrometry LC-MS/MS (n = 18). A biofilm composed by five bacteria and one fugal (Candida albicans, Veillonella dispar, Streptococcus mutans, Streptococcus oralis, Actinomyces naeslundii and Fusobacterium nucleatum) was conducted for 64.5 hours on coated-discs. After this period, the viable cells of biofilms were determined (n = 12). The biofilms topography and organization were analyzed by SEM and by confocal laser microscopy. The data of viable cells and protein profile were evaluated statistically by Student's t test and SFE data by two-way ANOVA followed by Tukey's test with a significance level of 5%. The results showed no difference between the properties of roughness and topography in groups. A high peak of nitrogen was detected in the chemical composition of the nitride surface. The treatment did not alter the SFE, that increased in the presence of AP (p <0.001). Different protein adsorbed to nitride surface. The amount of viable cells in the biofilm formed on both surfaces was similar (p = 0.416), confirmed by microscopies. The number of viable cells of Streptococcus oralis and Fusobacterium nucleatum were higher in TiN. It was concluded that the cold plasma nitriding did not alter the titanium surface properties and did not affect the amount of biofilm. However, it increased the counts of Fusobacterium nucleatum and Streptococcus oralis and selected different proteins in AP / Mestrado / Protese Dental / Mestra em Clínica Odontológica

Os altos índice de sucesso dos implantes dentais e sua indicação crescente apresentam como limitação a contaminação bacteriana com a consequente doença peri-implantar. Os métodos de tratamento ainda não se apresentam claros e seguros, portanto, meios de prevenção que impeçam a formação de biofilme e inibam o crescimento bacteriano devem ser desenvolvidos e aplicados para impedir a falha dos implantes. O objetivo deste estudo foi avaliar a efetividade de um novo antimicrobiano nanoparticulado - o vanadato de prata (AgNO3) em diferentes concentrações (2,5%; 5% e 10%), aplicado sob a forma de filme superficial sobre diferentes substratos sugeridos para dispositivos da Implantodontia. Foram selecionados os materiais poliacetal, teflon e resina acrílica e os veículos glaze e esmalte para a aplicação do nanocomposto. Análises das propriedades físicas rugosidade superficial e dureza Rockwell superficial, assim como imagens obtidas por meio da Microscopia Eletrônica de Varredura (MEV), foram utilizadas para avaliar a resistência e alterações estruturais dos grupos e portanto, a viabilidade de aplicação clínica. A análise pelo método microbiológico do halo de inibição mostrou que as bactérias P. aeruginosa, E. coli, S mutans, E. faecalis e S. aureus tiveram inibição de crescimento; enquanto nas bactérias anaeróbias P. gingivalis e P. intermedia e na levedura C. albicans não foi demonstrada a atividade antibacteriana de AgNO3. O tipo de substrato utilizado e de veículo para a aplicação de AgNO3 não influenciaram nos resultados, com exceção do S. aureus que obteve maior diâmetro do halo de inibição quando aplicado com o glaze em comparação ao esmalte (p<0,05). A proporção do nanocomposto mostrou influência nos resultados, sendo que 10% se mostrou a mais eficaz em todas as bactérias, e de modo geral sem diferença estatística com a proporção de 5% (p<0,05). Apesar de proporções menores algumas vezes não mostrarem atividade antimicrobiana, estas provocaram menor alteração nas propriedades físicas dos materiais, sendo a proporção do AgNO3 proporcional ao aumento da rugosidade e dureza superficial. Os substratos e tipo de filme não influenciaram nos resultados da rugosidade superficial após a aplicação do tratamento superficial (p>0,05), entretanto a aplicação de 10% do nanocomposto causou a alteração superficial mais significativa (7,02 ± 2,99 Ra) (p<0,05). Na dureza superficial não foi encontrada alteração significativa com o aumento da concentração do AgNO3 no poliacetal e na resina acrílica (p>0,05), no entanto no teflon, 10% de AgNO3 não alterou significativamente os valores de resistência. Apesar dos filmes não influenciarem nos resultados, o substrato poliacetal demonstrou maior dureza com diferença estatística com os demais substratos (83,0 ±10,2 HR15Yadaptado) (p<0,05). As imagens obtidas no MEV comprovaram mudanças estruturais superficiais com a presença de mais picos e vales, em comparação a superfícies sem o tratamento antimicrobiano. Como conclusão, apesar de 10% ser a concentração do AgNO3 que atingiu um maior número de espécies, essa concentração deve ser ponderada sobre o seu uso, e avaliada em estudos futuros sobre a sua viabilidade de uso clínico em função das alterações nas propriedades físicas. / The high success rate of dental implants and their growing indications show the limitation of bacterial contamination with consequent peri-implant disease. The treatment methods have not yet clear and secure, thus means for preventing the deposition of biofilm and inhibit bacterial growth must be developed and implemented to prevent failure of implants. The aim of this study was to evaluate the effectiveness of a new nanoparticulate antimicrobial - vanadate silver (AgNO3) in different concentrations (2.5%, 5% and 10%), applied as a surface film on different substrates suggested for devices of Implantology. The materials polyacetal teflon and acrylic resin and vehicles enamel / glaze were selected for the application of nanocomposite. Analyzes of the physical properties surperficial roughness and superficial hardness Rockwell, as well as images obtained by scanning electron microscopy (SEM) were used to assess the strength and structural changes of the groups and therefore the feasibility of clinical application. A microbiological method for the analysis of inhibition zone shows growth inhibition on the bacterias P. aeruginosa, E. coli, S. mutans, E. faecalis and S. aureus; while the anaerobic bacteria P. gingivalis and P. intermedia and the yeast C. albicans has not been demonstrated antibacterial activity of AgNO3. The type of substrate used and the vehicle for the application of AgNO3 did not influence the results, with the exception of S. aureus with highest diameter of inhibition zone when applied with glaze compared to enamel (p<0.05). The proportion of the nanocomposite showed influence on the results, 10% proved the most effective in all bacteria, and generally no statistical difference in the proportion of 5% (p<0.05). Although smaller proportions sometimes do not show antimicrobial activity, these caused minor change in the physical properties of materials. The ratio of AgNO3 was proportional to the increase of roughness and hardness. The substrates and film type did not influence the results of the surface roughness after applying the surface treatment (p>0.05), however the application of 10% of the nanocomposite caused surface alteration more significant (7.02 ± 2.99 Ra) (p<0.05). In hardness was not found to significantly change with concentration of AgNO3 in the acrylic resin and the polyacetal (p> 0.05). However in teflon, 10% AgNO3 did not significantly alter the resistance values. Although the films do not influence the results, polyacetal substrate showed higher hardness with statistical difference with the other substrates (83.0 ± 10.2 HR15Yadaptado) (p <0.05). The SEM images proved superficial structural changes with the presence of more peaks and valleys compared to surfaces without antimicrobial treatment. In conclusion, despite 10% being the concentration of AgNO3 that reached the highest number of species, this concentration should be thought on its use, and evaluated in future studies on the feasibility of clinical use in accordance with changes in physical properties.

L’objectif de cette thèse est double : 1) contribuer à la production de connaissances dans le champ théorique de la didactique professionnelle sur les activités liées aux systèmes vivants ; 2) aider à la conception, à l’ingénierie pédagogique et à l’évaluation de l’EVAH VirTeaSy. L’examen de la littérature dans le domaine des EVAH dentaires montre que les EVAH « haptiques » semblent être les plus pertinents pour répondre aux problématiques de formation en implantologie. Cependant, bien que des études montrent leur efficacité du point de vue de l’apprentissage, il reste des problèmes à résoudre en termes de méthodologie de conception. En effet, la démarche de conception s’appuie couramment sur des collaborations entre experts métiers et informaticiens qui aboutissent au développement d’EVAH technocentrés. Afin de contourner les écueils constatés dans ce type de démarche, nous choisissons d’inclure les sciences humaines sur l’ensemble du processus de conception de l’EVAH. Pour identifier les compétences à viser dans l’EVAH, nous mobilisons, dans le cadre de la didactique professionnelle, une analyse de l’activité. Celle-ci se finalise par l’identification de la structure conceptuelle de la situation reposant sur des concepts organisateurs de l’activité en liens avec des variables et des indicateurs. Notre première étude s’attache ainsi à identifier la structure conceptuelle de la situation en implantologie dentaire. Au cours de situations réelles de pose d’implant dentaire, des données d’enregistrement ont été recueillies et complétées par des verbalisations obtenues lors d’entretiens d’auto-confrontation. L’analyse des données à l’aide de la méthodologie des catégories conceptualisantes nous a permis de faire émerger les concepts organisant l’activité des dix chirurgiens-dentistes observés. L’activité d’implantologie consiste à réaliser un compromis entre le concept organisateur « d’émergence » qui permet de réaliser le projet prothétique et le concept « d’ancrage » qui permet au projet prothétique de durer dans le temps. Ces deux concepts n’étant pas toujours convergents. La conception de VirTeaSy s’appuie sur les résultats de l’étude 1 et se réalise grâce à une méthodologie en cinq étapes. Notre expérience de cette mise en œuvre méthodologique montre qu’il faut constamment faire des choix. Ces choix reposent dans un premier temps sur la littérature et conduisent à définir des éléments de conception généraux. Ces éléments sont ensuite spécifiés à l’aide des résultats de l’analyse de l’activité, celle-ci prend alors toute sa pertinence afin que l’EVAH traduise les compétences-clefs que les apprenants doivent construire pour être efficaces. L’étude 2 porte sur le transfert d’apprentissage du virtuel au réel. Pour ce faire, trente-deux dentistes sont répartis de façon aléatoire dans trois groupes : un groupe (n=10) nommé GRV formé dans VirTeaSy, un groupe (n=11) nommé GT formé de manière traditionnelle et un groupe (n=11) nommé contrôle (GC) ne recevant aucune formation. Tous les sujets sont novices en implantologie dentaire. Une semaine après que chaque groupe ait suivit sa formation, tous les sujets réalisent la tâche de réinvestissement consistant à poser un implant sur un cadavre humain. Pour chaque sujet, nous mesurons, à l’aide d’un scanner, la différence entre la performance demandée et la performance réalisée. Les mesures portent sur l’angulation, l’émergence et la centration. Nos résultats ne montrent pas de différence significative entre les trois groupes. Des prolongements à cette thèse sont en cours de mise en œuvre. Il s’agit : 1) d’étendre l’analyse de l’activité à une population internationale ; 2) d’évaluer VirTeaSy grâce à différents protocoles incluant les fonctionnalités issues de l’analyse de l’activité ; 3) d’élargir le périmètre de formation de VirTeaSy à l’odontologie. / The objective of this thesis is twofold: 1) to build knowledge in the theoretical field “didactique professionnelle” for living systems activities; 2) to help design and assess VirTeaSy. An analysis of the literature in dental V.E.T showed that “haptic V.E.T.” seem to be the most relevant for the challenge of training in dental implantology. However, some studies show, there are still problems to be solved in terms of design methodology. Indeed, the usual design approach relies on collaboration between dental experts and IT engineers. In this approach, IT engineers carry on the V.E.T. development. This means that the result is often a V.E.T. developed from an IT point of view rather than from a learning point of view. To overcome issues associated with this type of approach, we have chosen to include experts in pedagogy in design process of Virteasy.We have undertaken an analysis of activity within the framework of “didactique professionnelle” in order to identify the skills which the students were going to learn with our V.E.T. The final aim of this analysis is identification of the “conceptual structure of the situation” (structure conceptuelle de la situation) based on “organizing concepts” (concept organisateur) of the activity links with variables and indicators. Our first study deals with identifying the “conceptual structure of the situation” in dental implantology. Recorded data (movies) were gathered from ten dentist experts during a live implant surgery. This was followed by in depth interviews within the dentists watching the recording of the surgery and verbalizing their mental process during the procedure. A content analysis of the interview showed that the mental process of the dentist performing an implantology procedure is based on two concepts. The first is concept is “emergence”, the dentist’s actions are guided by the prosthetic teeth which is going to be fitted on the implant. The second is “anchorage”, the dentist’s action are guided by the longevity of the implant. These two concepts are not always compatible which shows the real challenge faced by implant experts. VirTeaSy design is based on the results of Study 1 and make with a five-step methodology Our experience shows that a lot decision have to be made at each stage of the methodology. These decisions were based initially on literature and led to the definition of general design elements. These components were then specified using the results of the activity analysis. This showed how important and relevant an activity analysis was in making specific and accurate decisions in the design of V.E.T. Because of this process, the V.E.T. is enable to teach skills and competences that students must acquire to perform procedures in real life situations. The study 2 focused on learning transfer from virtual to reality. To do this, thirty-two dentists are randomized into three groups: one group (n = 10) named Group with Virtual Training (GVT); one group (n = 11) named Group with Traditional Training (GTT) and one group (n = 11 ) named Control Group (CG) receiving no training. All subjects were novice to dental implantology. One week after training, all subjects had to perform a task during which they had to demonstrate and apply the skills acquired during the training (“the reinvestment” task consisting of placing an implant on a human corpse). For each subject, we measured the difference between the required performance and the performance achieved using a scanner. We recorded three kind of measure: angle; depth and center. The results showed no significant difference between the three groups. Extensions of this thesis are being implemented. Some are based on international partnerships with well-known Universities. These extensions are: 1) to extend the activity analysis to an international population, 2) To evaluate VirTeaSy through various protocols including features from the activity analysis, 3) To broaden the scope of using VirTeasy in dental training.

La réparation de l’humain est un secteur d’activité qui nécessite les compétences en sciences médicales et sciences dites «dures». Dans de nombreux cas, tout ou partie d’un organe doit être remplacé par un substitut en matériau inerte. C’est par exemple le cas en implantologie où l’on s’intéresse au remplacement de dents. La pose d’un implant dentaire est un acte chirurgical qui consiste à introduire dans l’os de la mandibule un dispositif en matériau inerte destiné à recevoir la couronne dentaire. Ces prothèses sont plus ou moins tolérées par l’organisme vivant (environ 5% de rejet) et peuvent dans certains cas conduire à une ruine de l’os ou engendrer des infections connues sous le nom de péri-implantite. Pour améliorer la biocompatibilité de ces dispositifs médicaux, plusieurs pistes sont explorées. On peut s’intéresser à la géométrie de l’implant et son état de surface, au matériau de l’implant ou bien au système mécanique implant-os. C’est dans ce dernier cadre que nous avons situé notre travail de thèse. Le système os/dent est un système mécanique soumis à des sollicitations répétées de forte intensité. Les niveaux de contrainte et de déformation atteints lors de la mastication participent à la stabilité de l’ensemble et la viabilité de ces milieux vivants. Ces niveaux de contrainte et de déformation doivent être reproduits dans l’os dans le cas du système implant-os. On espère ainsi assurer la viabilité de l’os et éviter les divers processus de dégradation. Il convient donc de simuler et analyser la réponse d’un tel système à des sollicitations mécaniques. Ce travail nécessite la modélisation du comportement de l’os et de l’implant. Ce dernier est considéré comme un matériau métallique classique sollicité dans son domaine de déformation élastique. Pour ce qui est l’os, son observation fine révèle sa nature multi-échelle et nous avons choisi de modéliser son comportement par une particularisation du milieu micromorphique de Eringen. Plus précisément nous l’avons considéré comme un milieu élastique micropolaire. Pour résoudre les équations de champs du problème, il a été nécessaire de développer un outil numérique spécifiquement dédié. Cet outil est basé sur une combinaison astucieuse de la méthode des éléments de frontières et d’une méthode sans maillage (meshless), plus précisément une méthode de collocation par points. Dans un premier temps, afin de comprendre le principe de la méthode, nous avons développé l’outil numérique pour résoudre une équation de champ scalaire, ici équation de la conduction thermique transitoire. Nous avons pu constater l’efficacité de la méthode pour des systèmes en trois dimensions. Dans un second temps nous avons adapté notre méthode numérique pour résoudre des équations de champ vectoriel qui sont dans notre cas les équations pour les milieux élastiques micropolaires. L’outil numérique a été validé sur un nombre d’exemples possédant une solution analytique ou en comparaison aux résultats de la littérature sur d’autres types de problèmes. L’outil a ensuite été appliqué à l’analyse du système implant-os. Pour comprendre l’apport de la microstructure d’un milieu élastique micropolaire, en comparaison à un milieu élastique classique, nous avons fait différentes études du système implant-os sous sollicitations mécaniques diverses en considérant les deux types de modélisation pour l’os. Les paramètres macroscopiques pour un milieu élastique micropolaire sont les mêmes que pour un milieu élastique classique. Les différences obtenues ne proviendront que de l’apport de la microstructure. Les résultats obtenus montrent que la modélisation fine du comportement mécanique adoptée pour l’os est réaliste au regard des contraintes induites par la sollicitation et à la diminution notable des sauts de contraintes à l’interface os/métal comparé au cas de la modélisation de l’os comme un milieu élastique classique. Ces résultats ont d’ores et déjà permis de comprendre certaines observations cliniques. / The repair of the human is a sector of activity which requires skills in medical sciences and sciences known as "hard". In many cases, all or part of an organ must be replaced by a substitute made of inert material. This is for example the case in implantology where one is interested in the replacement of teeth. The installation of a dental implant is a surgical act which consists in introducing into the bone of the mandible a device made of inert material intended to receive the dental crown. These prostheses are more or less tolerated by the living organism (about 5% of rejection) and can in some cases lead to a bone ruin or cause infections known as peri-implantitis. To improve the biocompatibility of these medical devices, several tracks are explored. We can focus on the geometry of the implant and its surface condition, the material of the implant or the mechanical bone / implant system. It is in this last frame that we located our work of thesis. The bone / tooth system is a mechanical system subject to repeated intense stress. The levels of stress and deformation achieved during chewing contribute to the overall stability and viability of these living media. These stress and strain levels must be reproduced in the bone in the case of the bone / implant system. It is hoped to ensure the viability of the bone and to avoid the various processes of degradation. It is therefore necessary to simulate and analyze the response of such a system to mechanical stresses. This work requires modeling the behavior of the bone and the implant. The latter is considered as a conventional metallic material stressed in its field of elastic deformation. As for the bone, its fine observation reveals its multi-scale nature and we have chosen to model its behavior by a particularization of Eringen's micromorphic environment. More precisely we have considered it as a micropolar elastic medium. To solve the field equations of the problem, it was necessary to develop a dedicated digital tool. This tool is based on a clever combination of the boundary element method and a meshless method, more precisely a collocation method. At first, in order to understand the principle of the method, we developed the numerical tool to solve a scalar field equation, here equation of transient thermal conduction. We have seen the effectiveness of the method for three-dimensional systems. In a second time we adapted our numerical method to solve vector field equations which are in our case the equations for the micropolar elastic media. The digital tool has been validated on a number of examples having an analytical solution or in comparison with the results of the literature. The digital tool was then applied to the analysis of the bone / implant system. To understand the contribution of the microstructure of a micropolar elastic medium, compared to a conventional elastic medium, we made different studies of the implant / bone system under various mechanical stress considering both types of modeling for the bone. The macroscopic parameters for a micropolar elastic medium are the same as for a conventional elastic medium. The differences obtained will come only from the contribution of the microstructure. The results obtained show that the fine modeling of the mechanical behavior adopted for the bone is realistic with regard to the stresses induced by the stress and to the noticeable decrease of the stress jumps at the bone / metal interface compared to the case of the modeling of the equivalent classic elastic medium. These results have already made it possible to understand certain clinical observations.

<p>The present work expose a technique of estimation of optimal direction for placing dental implant. A volumetric computed tomography (CT) scan is used as a help of the following searches. The work offers criteria of the optimal implant placement direction and methods of evaluation on direction’s significance. The technique utilizes structure tensor to find a normal to the jawbone surface. Direction of that normal is then used as initial direction for search of optimal direction.</p><p>The technique described in the present work aimed to support doctor’s decisions during dental implantation treatment.</p>

The present work expose a technique of estimation of optimal direction for placing dental implant. A volumetric computed tomography (CT) scan is used as a help of the following searches. The work offers criteria of the optimal implant placement direction and methods of evaluation on direction’s significance. The technique utilizes structure tensor to find a normal to the jawbone surface. Direction of that normal is then used as initial direction for search of optimal direction. The technique described in the present work aimed to support doctor’s decisions during dental implantation treatment.

Os altos índice de sucesso dos implantes dentais e sua indicação crescente apresentam como limitação a contaminação bacteriana com a consequente doença peri-implantar. Os métodos de tratamento ainda não se apresentam claros e seguros, portanto, meios de prevenção que impeçam a formação de biofilme e inibam o crescimento bacteriano devem ser desenvolvidos e aplicados para impedir a falha dos implantes. O objetivo deste estudo foi avaliar a efetividade de um novo antimicrobiano nanoparticulado - o vanadato de prata (AgNO3) em diferentes concentrações (2,5%; 5% e 10%), aplicado sob a forma de filme superficial sobre diferentes substratos sugeridos para dispositivos da Implantodontia. Foram selecionados os materiais poliacetal, teflon e resina acrílica e os veículos glaze e esmalte para a aplicação do nanocomposto. Análises das propriedades físicas rugosidade superficial e dureza Rockwell superficial, assim como imagens obtidas por meio da Microscopia Eletrônica de Varredura (MEV), foram utilizadas para avaliar a resistência e alterações estruturais dos grupos e portanto, a viabilidade de aplicação clínica. A análise pelo método microbiológico do halo de inibição mostrou que as bactérias P. aeruginosa, E. coli, S mutans, E. faecalis e S. aureus tiveram inibição de crescimento; enquanto nas bactérias anaeróbias P. gingivalis e P. intermedia e na levedura C. albicans não foi demonstrada a atividade antibacteriana de AgNO3. O tipo de substrato utilizado e de veículo para a aplicação de AgNO3 não influenciaram nos resultados, com exceção do S. aureus que obteve maior diâmetro do halo de inibição quando aplicado com o glaze em comparação ao esmalte (p<0,05). A proporção do nanocomposto mostrou influência nos resultados, sendo que 10% se mostrou a mais eficaz em todas as bactérias, e de modo geral sem diferença estatística com a proporção de 5% (p<0,05). Apesar de proporções menores algumas vezes não mostrarem atividade antimicrobiana, estas provocaram menor alteração nas propriedades físicas dos materiais, sendo a proporção do AgNO3 proporcional ao aumento da rugosidade e dureza superficial. Os substratos e tipo de filme não influenciaram nos resultados da rugosidade superficial após a aplicação do tratamento superficial (p>0,05), entretanto a aplicação de 10% do nanocomposto causou a alteração superficial mais significativa (7,02 ± 2,99 Ra) (p<0,05). Na dureza superficial não foi encontrada alteração significativa com o aumento da concentração do AgNO3 no poliacetal e na resina acrílica (p>0,05), no entanto no teflon, 10% de AgNO3 não alterou significativamente os valores de resistência. Apesar dos filmes não influenciarem nos resultados, o substrato poliacetal demonstrou maior dureza com diferença estatística com os demais substratos (83,0 ±10,2 HR15Yadaptado) (p<0,05). As imagens obtidas no MEV comprovaram mudanças estruturais superficiais com a presença de mais picos e vales, em comparação a superfícies sem o tratamento antimicrobiano. Como conclusão, apesar de 10% ser a concentração do AgNO3 que atingiu um maior número de espécies, essa concentração deve ser ponderada sobre o seu uso, e avaliada em estudos futuros sobre a sua viabilidade de uso clínico em função das alterações nas propriedades físicas. / The high success rate of dental implants and their growing indications show the limitation of bacterial contamination with consequent peri-implant disease. The treatment methods have not yet clear and secure, thus means for preventing the deposition of biofilm and inhibit bacterial growth must be developed and implemented to prevent failure of implants. The aim of this study was to evaluate the effectiveness of a new nanoparticulate antimicrobial - vanadate silver (AgNO3) in different concentrations (2.5%, 5% and 10%), applied as a surface film on different substrates suggested for devices of Implantology. The materials polyacetal teflon and acrylic resin and vehicles enamel / glaze were selected for the application of nanocomposite. Analyzes of the physical properties surperficial roughness and superficial hardness Rockwell, as well as images obtained by scanning electron microscopy (SEM) were used to assess the strength and structural changes of the groups and therefore the feasibility of clinical application. A microbiological method for the analysis of inhibition zone shows growth inhibition on the bacterias P. aeruginosa, E. coli, S. mutans, E. faecalis and S. aureus; while the anaerobic bacteria P. gingivalis and P. intermedia and the yeast C. albicans has not been demonstrated antibacterial activity of AgNO3. The type of substrate used and the vehicle for the application of AgNO3 did not influence the results, with the exception of S. aureus with highest diameter of inhibition zone when applied with glaze compared to enamel (p<0.05). The proportion of the nanocomposite showed influence on the results, 10% proved the most effective in all bacteria, and generally no statistical difference in the proportion of 5% (p<0.05). Although smaller proportions sometimes do not show antimicrobial activity, these caused minor change in the physical properties of materials. The ratio of AgNO3 was proportional to the increase of roughness and hardness. The substrates and film type did not influence the results of the surface roughness after applying the surface treatment (p>0.05), however the application of 10% of the nanocomposite caused surface alteration more significant (7.02 ± 2.99 Ra) (p<0.05). In hardness was not found to significantly change with concentration of AgNO3 in the acrylic resin and the polyacetal (p> 0.05). However in teflon, 10% AgNO3 did not significantly alter the resistance values. Although the films do not influence the results, polyacetal substrate showed higher hardness with statistical difference with the other substrates (83.0 ± 10.2 HR15Yadaptado) (p <0.05). The SEM images proved superficial structural changes with the presence of more peaks and valleys compared to surfaces without antimicrobial treatment. In conclusion, despite 10% being the concentration of AgNO3 that reached the highest number of species, this concentration should be thought on its use, and evaluated in future studies on the feasibility of clinical use in accordance with changes in physical properties.

Submitted by MARCIA ROVADOSCHI (marciar@unifra.br) on 2018-08-17T20:13:05Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_JoseSolonDaSilvaJunior.pdf: 4702814 bytes, checksum: f3853067fbfa9aca7b0ecd88eaf5c6e9 (MD5) / Made available in DSpace on 2018-08-17T20:13:05Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_JoseSolonDaSilvaJunior.pdf: 4702814 bytes, checksum: f3853067fbfa9aca7b0ecd88eaf5c6e9 (MD5) Previous issue date: 2018-03-28 / Recent studies demonstrate the effectiveness of nanostructures in dentistry. Some applications reduce physiological implications, such as the non-acceptance of a dental implant by the body. A promising nanostructure in several areas of knowledge that has been little explored for this purpose is graphene. In this work, we studied the interaction of adsorbed graphene with phosphorus (P), silver (Ag) and calcium (Ca) atoms with titanium dioxide clusters (TiO2), with nomenclature (TiO2)n, with n varying from 1 to 3. The aim of this study is to identify systems that are relevant to the area of implantology, i. e., nanosystems that could facilitate the adhesion of the implant to the organism. The dopant atoms were chosen because of their biocompatibility with bone tissue (P and Ca) and antibacterial properties (Ag). The clusters of TiO2 were used to mimic the oxide that is usually formed on titanium implants. For this, we performed calculations of first principles, based on the Density Functional Theory, as implemented in the SIESTA code. The exchange and correlation potential was treated within the generalized gradient approximation and the description of the valence electrons was done using the pseudopotential method. The results showed that the interaction of graphene adsorbed with calcium with TiO2 clusters is the most promising system that meets the purposes of the work. The adsorption energies for this case vary from 2.41 eV to 4.70 eV, indicating a strong interaction. In the case of silver-adsorbed graphene, the adsorption energies are lower, but still characterize a strong interaction, which varies from 1.31 eV for the cluster with n = 2 and 2.05 eV for the cluster with n = 3. For the cluster with n = 1, the value found for the adsorption energy was 1.92 eV. The system that was not relevant to the objectives of this work was the graphene adsorbed with phosphorus interacting with the clusters. In this case, the adsorption energies were high, 3.42 eV for (TiO2)1, and 2.16 eV for (TiO2)3, however, we observed that the cluster removed the atoms adsorbed from the graphene. For the cluster (TiO2)2, the interaction was weak, with an adsorption energy of 0.46 eV. These results, while theoretical, show that graphene can be a potential candidate for the creation of thin films to be used in the coating of titanium implants. / Estudos recentes demonstram a eficácia do emprego de nanoestruturas na odontologia. Certas aplicações reduzem implicações fisiológicas como, por exemplo, a não aceitação de um implante dentário pelo organismo. Uma nanoestrutura promissora em várias áreas do conhecimento e que tem sido pouco explorada para este fim, é o grafeno. Assim, neste trabalho, estudamos a interação do grafeno adsorvido com átomos fósforo (P), prata (Ag) e cálcio (Ca) com clusters de dióxido de titânio (TiO2), com nomenclatura (TiO2)n, onde n varia de 1 a 3. O objetivo desse estudo consiste em apontar sistemas que sejam relevantes para a área de implantodontia, ou seja, nanosistemas que pudessem facilitar a adesão do implante ao organismo. Os átomos dopantes foram escolhidos por apresentar biocompatibilidade com o tecido ósseo (P e Ca) e propriedades antibactericidas (Ag). Já os clusters de TiO2 foram utilizados com o intuito de mimetizar o óxido que geralmente se forma sobre os implantes de titânio. Para isso, realizamos cálculos de primeiros princípios, baseados na Teoria do Funcional da Densidade, conforme implementado no código SIESTA. O potencial de troca e correlação foi tratado dentro da aproximação do gradiente generalizado e a descrição dos elétrons de valência foi feita utilizando o método de pseudopotenciais. Os resultados obtidos mostraram que a interação do grafeno adsorvido com cálcio com os clusters de TiO2, é o sistema mais promissor que atende os propósitos do trabalho. As energias de adsorção para esse caso variam de 2,41 eV a 4,70 eV, indicando uma interação forte. Já para o caso do grafeno adsorvido com prata, as energias de adsorção são mais baixas, mas ainda assim caracterizando uma interação forte, as quais variam de 1,31 eV para o cluster com n = 2 e 2,05 eV para o cluster com n = 3. Para o cluster com n = 1, o valor encontrado para a energia de adsorção foi de 1,92 eV. O sistema que não se mostrou relevante para os objetivos do trabalho foi o grafeno adsorvido com fósforo interagindo com os clusters. Nesse caso, as energias de adsorção foram altas, 3,42 eV para o (TiO2)1, e 2,16 eV para o (TiO2)3, porém, observamos que o cluster afastou o átomos adsorvido do grafeno. Para o cluster (TiO2)2, a interação foi fraca, com uma energia de adsorção de 0,46 eV. Esses resultados, embora teóricos, mostram que o grafeno pode ser um candidato potencial para a criação de filmes finos, a serem utilizados no revestimento de implantes de titânio.